Method of and apparatus for indexing dials



" March 27, 194.5. l E, PENKER 2,372,389

METHODS OF AND APPARATUS FOR INDEXING DIALS Filed May l2, 1942 2 Sheetsf-Sheet l a0 l Am 35 .36 4o l "f 3l32b 32a 3:10. 37 l 27 45 Z8 27a 24 24- 27 Z7 43 MII REU. i

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INVENTOR.

March 27, 1945. E, PENKER 2,372,39

METHODSfOF AND APPARATUS FOR INDEXING DIALS Filed May 2, 1942 2 Sheets-Sheet 2 ,5 :fi q. E. 431 25 z5 27 25 z5 l .l l, i x C@ t l I fifa f//9 INVENToR. ERNEST Ps/wfER ATTORNEY Patented Mar. 27, 1945 METHOD' 0F AND APPARATUS FOR INDEXING DIALS Ernest Penker, Flushing, N. Y., assignorto Etched Products Corporation, Long Island CityN.. Y., a corporation `of New York Application May 2, 1942, dSerial No. 441,436

4 Claims. (Cl. T01- 4) This invention relates generally to the manufacture of index dials and the like., as used in in dicating instruments and similar devices, and is more particularly directed to a method and means for forming indicia, as numerals., letters `and other Vcharacters or symbols, upon stamped or drawn metal dials, under pressure, `to effect a partial displacement of the dial material for the formation of the defining surfaces thereof, in a sub-surface relationship, to the face of the dial.

In producing index dialssuch, for example, as

are essential in the assembly of certain types of aircraft indicating instruments, the indicia, usually numerals, .have been impressed orstamped on .the dial surface by utilizing a conventional set-up of oomplemental male and female dies, the female die being entered inthe dial, which .is in the yform of an annulus with an integral base ange, to coact with the male die, as lthe latter is pressed into the outer periphery or face of `the dial, in accordance with .standard practice. While certain numerals, letters or other symbols may be fairly clearly defined in producing the impressions by the use of the complemental male and female dies, those characters or symbols in which defining lines or surfaces intersect Yor merge into others of a different order or diferentrelative disposition, are not cleanlyand sharply delineated. For instance, the jointure or merger of a horizontal line or surface with avertical or obliquev one, as in the formation of the numeral 4 or the 'junction of intersecting lines, as the diagonal lines constituting the letter 33, instead of being sharply and angularly delineated, as is requisite to va uniformly clean-cut readily readable imprint, is obscured by a more or less irregular llet' or web-like vconnection between the lines. This lack of uniformly clear and sharp definition of all of the characters vcarried by the dial, it has been found, detrimentallyaffects the serviceability of the instrument in which the dial is designed to function, under variable and frequently abnormal conditions of use;

To .overcome the unsatisfactory results which ow from the employment of the conventional male and female die methods and obtain the `required uniformity and complete clarity ofdenition of lall of the characters or symbols, it lhas been proposed to resort to engraving, or, as an Whichihey sfetolbcome spart;

Therefore, it is the primary Vobject of this Linvention to provide a simple, eicient and .economical method -of .producing characters, as numerals, letter's'or *other symbols'upon stamped or drawn articles, as index dials, for indicating :instruments and the like, which will insure uniformly clear and sharply delineated characters, irrespective of the relative arrangement or disposition of their component `defining lines, the'objection* able malformation of meeting Iand intersecting lines at their points of merger or jointure, which results from the use of the conventional .male and female die stamping operations, as .hereinbefore -set forth, being entirely eliminated.,

More speciiioallm it is an important object of this invention to provide a .method of forming charactersas aforesaid, on metal index dials, under pressure, to dispiace the dial material out- Wardly of the peripheral surface, from which the characters are `to be viewed, as by coning, in a manner, whereby the displacement of material will be accurately controlled, directionally and otherwise, to produce a groove-outlined character in the dial surface, unmarred .by irregularities in 'the groove-defining or immediately adjacent surfaces, vespecially' at those points where grooves intersect or connect one with another, the m-ajor displacement of .metal being removed by machining .following the coining step.

It is also lan important object of this invention to provide a simple and `economical means 'or apparatus for vpracticing my method, whereby index ydials may be rapidly and economically produced, with the elimination of those imperfections that are concomitant to the production of characters of the grooved-outline type, by standard .male and .female die processes, thus reducing thewaste of material that results from the discarding of imperfect dials and greatly accelerating the aggregate output of dials over a given period.

A further object of my invention is to provide a mechanism for carrying my method into effect, as aforesaid, `in whichl a series of characters, as numerals, letters `or the like, may be simultaneously impressed on the circumferentialface of a dial, in a coiningaction wherein therequisite impressionfforming dies are concurrently urged into contact with the face of the dial and the impressions produced therein., in a continuing unif form lmovement. thereof, under sustained and I gradually increasing pressure.

Other objects and `advantages flowing from the practicing of my invention will become manifest as the descriptionproceedanandl would have it understood that my invention may be utilized in the application of grooved-outline characters to articles other than index dials of the form herein disclosed, within the spirit and scope of the appended claims.

In the accompanying drawings, I have shown a preferred form of mechanism for practicing my method, and a type of index dial which may` be produced thereby, together with fragments of dial surfaces showing a numeral as produced by my method and by methods now employed, for comparative purposes.

In the drawings: l

Figure l is a sectional elevation of a preferred embodiment of a coining or impression-forming mechanism, which may be advantageously employed in practicing my method.

Fig. la is a fragmentary enlarged sectional view, showing portions of the work-supporting element and cooperating pressure head in the position they assume at the beginning of the coining operation.

Figure 2 is a top plan view of a portion of the Work-supporting element of the structure of Fig. 1, showing the relative disposition thereon of the concurrently actuatable dies and the cooperating work-retaining anvil.

Figure 3 is an exaggerated fragmentary view of an arcuate section of a dial, with a grooveforming portion of a die face entered therein, to

disclose the manner in which the dial metal is displaced under the 'sustained and increasing die pressure.

Figure 4 is a view similar to Figure 3, showing the displaced excess metal removed from the face of the dial, following the completion of the coining operation.

Figure 5 is a view in perspective of an index dial in the form of an annulus, embodying an inturned attaching or mounting flange.

Figure 6 is an elevational View of a fragment of adial, illustrating the clear denition of a numeral formed by my coining method, and

Figure 7 is a similar View, illustrative of the relative imperfections that would occur in the same numeral, as produced in the conventional stamping process.

Referring now to the drawings in detail, in which like characters of reference are employed to designate similar parts in the several views, I0 indicates the bed of an apparatus for practicing my method, embodying a rectangular recess I I which may be formed by a suitable frame xed to the bed surface, two of the members of which are indicated at I2 and I3. Projecting upwardly from the center of the aforesaid recess is a pin I4 having a head I5 countersunk in said bed and xed thereto, as by the bolts I6, the end of said pin being slightly tapered or o-f a conical formation, as at I4a, for the purposes which will be explained.

A rectangular table I'I complemental to the recess I I is supported in normally spaced relation to the bed I for relative vertical movement, by a plurality of expansion coil springs I8, the ends of which are engaged in the seats I9 and 20, formed in the opposed surfaces of the table and bed respectively, a spring being located in proximity to each corner of the table, so as to .maintain it in a horizontal position. As will be noted, the table I'I is centrally bored, as at Illa, to providea bearing for the aforesaid pin I4 which functions as a guide in the movement of the table in opposition to and under the influence of its supporting springs, relatively to said bed I0.

A work-retaining anvil, composed of two separate approximately semi-annular sections 2| and 2Ia, is located centrally of the table Il, the respective anvil sections being connected to the table by the screws 22 and 22a for relative horizontal 'movement within the limits defined by the cooperating elongated slots 23 and 23a. formed in said anvil sections, as shown in Figure 2. The opposed surfaces of the two anvil rsections are centrally recessed for the reception of the pin I4, the upper portions of the respective recesses being of reduced diameter, as at 24 and 24a, for engagement by the tapered portion I4a of said 1 pin, in a camming action tending to separate said anvil sections, as the table is moved downwardly over the pin in opposition to the springs I8, for ultimate disposition upon the bed within the recess II, preliminary to the performance of the coining operation, as will be hereinafter set forth in greater detail.

Radially disposed on the table Il, I provide a series of guideways 25 of a V or other suitable cross-section, in which complemental dependent tongues 26 of the dies 2I are adapted to be entered for movement of the dies longitudinally of the guideways, in opposition to and under the influence of the springs 28, located within the guideways, in engagement with suitable stops 29 therein and the-tongues 26 of said dies. The guideways 25 terminate in spaced relation to the anvil, the springs being effective upon the dies to urge them to a normal position in which their vertical impression-forming faces 21a are likewise spaced from the anvil, as clearly shown in Figure of the dies being readily inserted from the outer ends of the guideways to locate the dies in engagement with the guideway surfaces on which they bear, the mechanism herein shown being designed for the simultaneous production of twelve 'die-impressions. Of course, a mechanism may embody a greater or lesser number of guideways to accommodate the required dies.

Reciprocable within a suitable bearing 30 and normally disposed in vertically spaced relation to the table II, is a pressure head 3l of an area in excess of that of the bed recess I I, which is undercut or recessed, as at 32, the dening Wall 32a of the recess being of a frustro-conical configuration, and having the terminal edge 32h to engage the inclined arcuate end surfaces 2'Ib of the dies 2'I in a camming action to urge the dies toward the anvil, as hereinafter described. The base of the recess 32 is annularly recessed, as at 33, for the reception of the work-engaging pressure disc 34 supported from the pins 35, reciprocable within the bearings 36 in said head. Springs 31 interposed between said disc and the head surface, act to expel the disc from said annular recess 33, which is provided with aper-v tures 34a for the reception of the protruding heads of the anvil section retaining screws 22 and 22a.

A pluralityof pins 38 having heads 3S reciprocable within the bores 40, normally are projected from the head 3| by the springs 4I, these pins, four ln numberjbeing preferably positioned in alinement with the table supporting springs I8, the head in juxtaposition to the pins 38 being bored, as at 42, to receive the complemental guide pins 43 carried by the table I1, contiguous to the four corners thereof, as shown in Figure 2,

'Assuming thata dial ofthe type show-nin Figure is to be imprinted or. indexed, it is placed in position upon the :sectional anvilv .with its iiange a uppermost, theA Wall b, which is to form the face -of the dial, being in the plane ofthe surroundingdie faces.. As thev pressure head ytl is lowered toward the table I'l, the guide pins 43 enter the head bores 112,` the pins 3S' contacting with the surface ofi the table in the, continuing downward movement of the head and initiating a like .directional movement ofthe table inopposition to its springs I8, as thel'atter yield under the. resistanc'eoffered by the heavier-springs '4I'. The continuing'downward movement ofthe table,

underpressure ofthe llatter springs, upon the pin I4. brings the latter into the area of the recess formedl in the opposed-surfaces ofthe anvil sections. and as the table is urged to its ultimate position in contact with the bed Il), the cam portion Ilia of said pin enters the 'reduced diameter portion 24a of theanvil and initiates a gradual separating movement of the anvil sections for engagement with the inner surfaces of the dial wall' bythe anvil sections reaching their extreme positions in'positive frictional engagement with the dial, when the table comes to rest within. the recess II. This gradual actuation of the anvil sections and the progressive increase in the pressure that is applied to the dial wall news' from the cushioning action of the springs I8 in con trolling the' descent of the table and the con;

current projection of the pin Illl therethrough between the anvil sections.. distortion of the'thin metal wall of the dial, as would result under the impact of' an abrupt expansion of the anvil sections is thus entirely eliminated.

As the table I1 reaches its position lWithin the recess II, the continued approach ofthe pressure head causes thesprings 4I to contract lto permit the disc 34 to yieldably abut upon the The kpossibility ofl beingY outwardly of the dial face and laterally of the grooves produced therein, as controlled by the spreading and erupting action of the wedgelike formation of the die faces as' they enter the metal in theformation of the grooves, whereby the characters are delineated on the dial. The expanded anvil, the periphery of which is complemental to the inner circumference of the dial, contributes to the limitation of the inward displacement of the dial. metal, as at y in Figures 3 and 4f, and a slight flattening or spreading thereof,.as the metal is extruded in the coining action of `the, mechanism.

kFollowing the completion ofthe coining operation, as justl described, the pressure head may be raised, to permtthe table to assume its normal position under the expanding action of the springs I8, whereupon the-dial may be freely lifted from the anvil sections. The dial is then subjected to a millingor other suitable machine operationfor eifecting the removal of the displaced or surplus metal a: from the face thereof. In this operation, only the outwardly displaced metal is removed, vso that on the conclusion of the machining, the original outer circumferential Y dimension of the annulus will remain unchanged.

By utilizing a; plurality of dies concurrently co-acting with the anvil, in the manner set forth, I amenabled to attain the heretofore described clean and sharp delineation in each character impressed inthe dial metal, in .a single continuing operation. Each constituent groove of a character is uniformly dened and the uniform displacement of the metal outwardly of the dial face, brought about by the co-action of the wedge-shaped die surfaces with the opposed dial A supporting. surfaces of the anvil, produces an flange .a of the dial, Yunder the control of the springs 31, the pressure imposed upon the dial by the discA increasing in the recession of the disc, concurrent with the engagement of the die ends 2lb by the edge 32h of the wall 32a of thel pressure head recess 32, as shown in Fig. 1a e The continuing descent of the head with its edge 3227 in engagement with the inclined surfaces 2'Ib ofthe ends of the dies, simultaneously produces a uniform movement of the dies toward thedial to contact with the face thereof andtransfer the characters delineated upon the die faces by wedge-like projecting surfaces* to the dial in a vcontinuingv movement, in which the pressure, effective axially of the dies, is ygradually increased as the edge 32h of the Wall 32o traverses the inclined curved surfaces 2lb of the dies, the dieA progression terminating in a final relatively abrupt pressure-applying movement, induced by the engagement of said edge `3212 with the sharp,

even distribution of the metal between the character-deiining grooves. This distribution of the surface metal, eliminates vthe .malformation or bulging in the area of the juncture of one groove with another, as where kone groove crosses another, or where two grooves meet, that is a common fault in the practicing of the conventional male and female die stamping processes, herein.. before referred to, and which results in irregularities'in the groove-defining lines andsurfaces at such points, or in the formation of undesired connecting vwebs or fillet-like surfaces therebe.- tween. Obviously, clear and sharp delineation of the characters in such circumstances, cannot beattained.

In Figure 6, I have illustrated the numeral 4 as it is produced on the face of a dial such as herein shown, by my method, while Figure 7 shows the same numeral as formed in a conventional male and female die operation. It will be observed that the numeral of Figure 6 is clear terminal edge 21e of the inclined die surface, to

complete the coining operation, the depth of the recessed portion 32 of the pressure head being just sufficient to permit of the engagement of the edge 32h with the edge 2'Ic, as aforementioned.

As the dial is subjected to the progresslvely 1ncreasing pressure of the entering dies, the metal of the dial, within the area in which the wedgelike surfaces of the die faces are effective, is displaced in opposite directions, inwardly and outwardly, in response to andunder the control of the die movement, the major displacement or. shifting of the metal, indicatedat'r in Figure 3,

cut land sharply delineated, the point at which the horizontal portion of the numeral merges. into or joins the vertical section thereof being den'ed by sharp angles, which produce' a perfectly formed and symmetrical character, while the appearance of the numeral of Figure 7 is marred by the Web-like or fillet connection between its horizontal and vertical portions, which interrupts the uniformity of the defining grooves.

From theforegoing, it will be manifest that I have provided a simple and highly practicable method of attaining the objectives of my invention, as hereinbefore set forth, together with a mechanism whereby my method may be practiced in a most eicient and economical manner.

I claim:

1. A mechanism for producing index dials and the like, comprising a fixed base, an expandible work-engaging anvil, a vertically movable support for said anvil, a plurality of radially disposed guideways on said support, each being adapted to receive a die for movement longitudinally thereof, each of said dies being provided at one end thereof with an inclined surface having a sharp terminal edge, yieldable means for normally maintaining said support in vertically spaced relation to said base, a downwardly movable head mounted above the support, pins projecting from said head for engaging the support in the downward movementI of the head and depressing the support into contact with said base, means rigid with said base for guiding the support in its movement toward the base and expanding said anvil to engage the work, said pins being yeldably mounted on the head to permit a continued downward movement of this latter subsequently to the depression of the support, and a surface formed on the head adapted to engage said inclined surfaces, of the dies during the continued downward movement of the head to progressively urge said dies toward the anvil into impression forming engagement with the work thereon, said surface of the head engaging said sharp terminalv edge of the inclined die surfaces at the end of the downward movement of the head to cause a final abrupt pressure applying movement of the dies.

2. A mechanism for producing index dials and the like, comprising a xed base, an expandible work-engaging anvil, a vertically movable support for said anvil,` a plurality of radially disposed guideways on said support, each being adapted tov receive a die formovement longitudinally thereof, each of said dies being provided at one end thereof with a cam surface having a sharp terminal edge, yieldable means for normally maintaining saidl support 'in vertically spaced relation to said base, a downwardly movable head mounted above the support, pins projecting from said head for engaging the support in the downward movement of the head and depressing the support into contact with said base means rigid with said base for guiding the supv port in its movement toward the base, said guide means being effective at a predetermined point in the movement of the support to expand said anvil to engage the work, said pins being yieldably mounted on the head to permit a continued Adownward movement of this latter subsequently to the depression of the support, and a surface formed on the head adapted to engage and traverse said cam surfaces of the dies during the continued downward movement of the head to progressively urge said dies toward the anvil to apply a gradually increasing impression forming pressure to the' work thereon, said surface of the head engaging said sharp terminal edge of the inclined die surfaces at the end of the downward movement of the head to cause a final abrupt pressure applying movement of the dies.

3. A mechanism for producing index dials and the like, comprising a fixed base, an expandible work-engaging anvil, a vertically movable support for said anvil, a plurality of radially disposed guideways on said support, each being adapted to receive a die for movement longitudinally thereof, each of said dies being provided at one end thereof with an inclined surface havin-g a sharp terminal edge, yieldable means for normally maintaining said support in vertically spaced relation to said base, a downwardly movable head mounted above the support, pins projecting from saidhead for engaging the support in the downward'movement of the head and depressing the support into contact with said base,

means rigid with said base for guiding the support in its movement toward' the base and eX- panding said anvil tovengage the work, said pins being yieldably mounted on the head to permit a continued downward movement of this latter subsequently to the depression of the support, means associated with the head and effective in the continued downward movement of this latter to yieldably press the work into engagement with the top of the anvil, and a surface formed on the head adapted to engage said inclined surfaces of the dies during the continued downward movement of the head to progressively urge said dies toward the anvil into impression forming engagement with the work thereon, said surface of the head engaging said sharp terminal edge of the inclined die surfaces at the end of the downward movement of the head to cause a final abrupt pressure applying movement of the dies.

4. A mechanism for producing index dials and the like, comprising a xed base, an expandible work-engaging anvil, a vertically movable support for said anvil, a plurality of radially disposed guideways on said support, each .being adapted to receive a die for movement longitudinally thereof, each of said dies being provided at one end thereof with an inclined surface having a sharp terminal edge, yieldable means for normally maintaining said support in vertically spaced relation to said base, a vertically movable head adapted to enga-ge the support and depress the same into contact with said base, means rigid with said base for guiding the support in its movement toward the base and expanding said anvil to engage the work, and a surface formed on the head adapted to engage said inclined surfaces of the dies in a continued downward movement of the head subsequently to the depresssion of the support, to progressively urge said dies toward the anvil into impression forming engagement with the work thereon, said surface of the head engaging said sharp terminal edge of the inclined die surfaces at the end of the downward movement of the head to cause a final abrupt pressure applying movement 0f the dies.

ERNEST PENKER. 

